i took me zed upto zedworld a few weeks ago for a conzultz test due to the boost not giving me the kick it used to be. jeff diagnosed the problem as retarded timing and put it right, all was good for a few hundred miles, but now its gone back to lacking power. is it possible for the the timing to go out in that short a time? i know the engine was rebuilt about 7000 miles ago so can only ssuming the timing belt was replaced then. also it has new hybrid turbos fitted

any ideas please

check your cas mate is it nipped up tight, after all the research ive done lately apparently they can move a little.